<element xmlns:prefix1="namespace" prefix1:attribute="some value">Some text</element>


<element xmlns:prefix2="namespace" prefix2:attribute="some value">Some text</element>

String control = "<prefix1:element xmlns:prefix1="namespace" prefix1:attribute="x">Some text</prefix1:element>";
    String test = "<prefix2:element xmlns:prefix2="namespace" prefix2:attribute="x">Some text</prefix2:element>";
    try
    {
        Diff diff = XMLUnit.compareXML( control, test );
        assertTrue( "Similar", diff.similar() );
        assertTrue( "Identical", diff.identical() );
    }
    catch ( Exception e )
    {
        fail( e.getMessage() );
    }

// identical
XMLAssert.assertXMLEqual(XMLUnit.compareXML(control, test), true)
// similar
XMLAssert.assertXMLEqual(XMLUnit.compareXML(control, test), false)

// Similar
XMLAssert.assertXMLEqual()

// Identical
XMLAssert.assertXMLIdentical()